2-(substituted-benzyl)-1, 3-propanedisulfonates



United States Patent 3,068,266 2-(SUBSTITUTED-BENZYL)-1,3- PROPANEDISULFONATES Raymond G. Wilkinson, Montvale, N.J., and Thomas L.

Fields, Pearl River, N.Y., assignors to American Cyanamid Company, New York, N.Y., a corporation of Maine No Drawing. Original application Ser. No. 748,589, July 15, 1958, now Patent No. 3,013,069, dated Dec, 12, 1961. Divided and this application Apr. 25, 1961, Ser.

3 Claims. (Cl. 260-456) This invention relates to new organic compounds and, more particularly, is concerned with novel substituted phenylethanes which may be represented by the following cu -oso -R.;

wherein R is hydrogen, hydroxy, lower alkyl or a lower alkoxy radical, R and R are hydrogen, halogen, hydroxy, lower alkyl, lower alkoxy or an aralkoxy radical, and R is lower alkyl or a mononuclear aryl radical. Suitable lower alkyl and lower alkoxy groups contemplated by the present invention are those having up to about 6 carbon atoms. Suitable aralkoxy groups are benzyloxy, phenthoxy, etc. Suitable aryl groups are benzene and toluene. Halogen is exemplified byhrornine, chlorine and iodine.

The novel compounds of the present invention are useful intermediates for the preparation of Z-carboxymethyl and 2-formylmethyl-4-oxotetrahydronaphthalenes which form the subject matter of the copending application of Raymond G. Wilkinson and Andrew S. Kende, Serial No. 821,093, filed June 18, 1959, which is a continuation-in-part of application Serial No. 748,613, filed July 15, 1958, now abandoned. The new compounds of this invention are also useful in the synthesis of polyoxygenated cyclic compounds.

The new compounds of this invention may be prepared -from the corresponding benzyl bromide according to the following reaction scheme:

3,068,266 Patented Dec. 11, 1962 salt is preferably carried out in a refluxing solution of a lower alkanol. The benzyl malonic ester so formed is reduced with lithium aluminum hydride in a conventional manner. The formation of the bis-sulfonates from the intermediate 1,3-propanediols is likewise conventional.

The invention will be described in greater detail in conjunction with the following specific examples.

Example 1 94.0 grams (0.6 mole) of 2-chloro-5-methoxytoluene [Peratoner and Condorelli, Gazz. Chirn. ltal., 28, I, 213 (1898)] are added to 600 milliliters of reagent grade carbon tetrachloride, 117.4 grams (0.66 mole) of N- bromosuccinimide and 0.1 gram benzoyl peroxide. The reaction mixture is stirred at reflux temperature and'addi tional 0.1 gram quantities of benzoyl peroxide are added after 1% and 18 hours. After 21 hours the volume of solvent is reduced to approximately 250 milliliters and the succinimide filtered off. The filtrate is washed with three 200 milliliter portions of Water, dried over anhydrous MgSO and filtered. The solvent is removed under reduced pressure and the residual oil crystallized on standing overnight. Yield of crude 2-chloro-5-methoxybenzyl bromide, 131.0 grams. The pure compound crystallizes from (2040) petroleum ether as white needles, melting point 55.557.5 C.

Example 2 131.0 grams (0.55 mole) of 2-chloro-5-methoxybenzyl bromide in 300 milliliters of absolute ethanol is added over a 1 hours period to a refluxing solution of diethyl malonate (145 grams, 0.9 mole) andsodiurn methylate (32.4 grams, 0.6 mole) in absolute ethanol. The refluxing is continued for an additional 2 /2 hours and the reaction mixture concentrated to approximately half volume. The sodium bromide is filtered off .and the filtrate acidified by the slow addition of acetic acid. The remainder of the solvent is removed under reduced pressure and the residual oil taken up in ether. The ethereal solution is washed with three 200 milliliter portions of water and dried over anhydrous MgSO The ether and excess diethyl malonate are removed under water pump pressure. Diethyl-2-chloro-5-methoxybenzyl-malonate is collected at 155-168 C./O.4O.8 mm.; yield: 90.0 grams; n 1.5030. Overall yield based on 2-chloro-5- methoxytoluene is 48%.

003i: H131 ,H-C

0on1: diethyl m $212+ R3 R. g 0 1 21 u -0e92,

H-CH GHQ-OH 05,343) E wherein R R R and R are as hereinbefore defined.

The reaction conditions are not especially critical. The

reaction of the benzyl bromide with diethyl malonate Example 3 A solution of grams (0.33 mole) of diethyl-2- chloro-5-methoxybenzylmalonate in 360 milliliters of dry point 41-46 0.

-ether is added slowly with stirring to 19.5 grams. (0.513

over the weekend. The ether layer is washed with. H O,

dried over MgSO and concentrated to an almost colorless oil which turns to a mushy solid on seeding. Distilglation at 0.1 mm. gives 64 grams (84%) of a colorless oil at 16 0 l75 C. With a small forerunat 130-160 'C. On seeding, the main fraction gives white crystals of 2-(2'-ehloro-5-rnethoxybenzyl)-1,3-propanediol, melting Example 4 solution of 2-(2'-chloro-5'-methoxybenzyl)-1,3-propanediol (100 grams,- 0.435 mole) in 500 milliliters ben- The precipitated white crystals are collected on a filter .and washed thoroughly with five 100 milliliter portions of benzene. The combined washings and filtrate are washed with-250 milliliters 1 -N sodium bicarbonate, then with 200 milliliters of water. The benzene layer is treated ,with' decolorizing carbon, dried with anhydrous magnesium sulfate and the volatile solvent removed in vacuo.

Yield of crude 2-(2'-chloro-5'-rnethoxybenzyl)-1,3-propanediol-bis-methanesulfonate is 172.3 grams (93.7%). Recrystallization of 148 grams of the crude material from 300 milliliters of n-butanol yields 135.0 grams of white I crystals. Melting point, 75 -77 C.

Example 5 To 1.5 grams (5.0 millirnoles) of 2-(2'chloro-5-meth-.

is added 2.20 grams (11.5 millimoles) of p-toluenesulfonylchloride. The solution was cooled to 0 C. and 1.0 milliliter of pyridine added. This mixture is allowed to stand for 4 days at 5 C. with a considerable amount of pyridine hydrochloride crystallizing out. The solution is filtered and the filtrate is extracted with dilute sodium bicarbonate solution. .The benzene layer is concentrated to a gum. This gum can be crystallized from ethanol and water to give white crystals of 2-(2-chloro- 5 '-methoxybenzyl -1, 3-prop anediol-bis-toluenesulfonate.

This application is a division of our copending application, Serial No. 748,589, filed July 15, 1958, now US. Patent No. 3,013,069, issued December 12, 1961.

What is claimed is:

1. A compound of the formula:

32 r I Y Hz #0502 I ca 'c v I.

. r w-a wherein R is selected from the group consisting of chloride, bromine and iodine, R is lower alkoxy, and R is selected from the group consisting of lower alkyl and .mononuclear aryl.

2. 2-(2-chloro-5'-methoxybenzyl)-l,3-propanediol-bismethanesulfonate.

3. 2-(2-chloro-5'-methoxybenzyl)-1,3-propanediol-bistoluenesulfonate.

References Cited in the file of this patent UNITED STATES PATENTS 3,013,069 Wilkinson et a1. Dec. 12, 1961 

1. A COMPOUND OF THE FORMULA: 